Redhat Linux AS 3 U7 can't detect 16 logical CPUs on DL760G2

[richeal75]

HW: DL760G2 with 8 physical CPUs , qty=2
SW: Redhat Linux AS3 U7

problem: Linux only can detect 8 CPUs after enabled Hyperthreading in RBSU.

customer has two DL760G2 servers , each server has same configuration (8 physical CPUS), and install same OS version:redhat linux AS3 U7 , but it very strange that Redhat Linux can detect 16 logical cpus on one server A , but only can detect 8 logical cpus on other serverB.

Move OS of Server A to server B , but serverA's OS still only can detect 8 logical cpus on Server B.

what 's the root cause ?

zhangyi

[Ivan Ferreira]

Maybe the kernel was booted with the noht option. The the kernel boot options.

[Steven E. Protter]

Shalom,

As a precaution make sure the systems firmware and such is up to date with the DL780 cd/dvd that is bootable and ships with the system.

Make sure you boot the system with a kernel, smp or hugement that supports multiple processors.

You may need to patch the system up to Update 8, there could be a bug or problem with the kernel.

SEP

[Ivan Ferreira · Accepted solution]

Now that you methion it, check if the operating system selection in the BIOS is correct.

[richeal75]

Dear ALL,

Problem resovled after changed OS selection to Linux in RBSU.

thanks for your help.

zhangyi.

[richeal75]

another thing : is there any document related the issue ? and customer need it.

[Ivan Ferreira]

This is a document that may help you. It describes the problem, it's a Microsoft document, but the same rules apply.

http://support.microsoft.com/?scid=kb%3Ben-us%3B252326&x=11&y=12